Carburetor



May 3, 1932. R. F. BRACKE 1,856,238

GARBURETOR Filed July 5, 1927 Patented May 3, 1932 UNITED STATES PATENTori-TCE RBERT F. BRACKE, F CHICAGO, ILLINOIS, ASSIGNOR T0 RTIS B. CAMP,TRIISTEE, OF GLENCOE, ILLINOIS CARBURETOR Application led J'uly 5, 1927.Serial No. 203,294.

My invention relates to improvements in economizers for carburetors.

An object of the invention is to provide an improved economizer for thecarburetor of an internal combustion engine, the function thereof beingto reduce the amount of fuel delivered to the induction chamber atnormal car speeds and load, and to permit maximum operation of the fueldelivery mechanism when the engine is idling or operating under fullload.

The invention will be explained as embodied in a carburetor of the typein which the amount of fuel delivered to the induction chamber isdependent upon the amount of air passing through a Venturi tubecomprising the fuel delivery means.

A further object is to provide an economizer for a carburetor in Whichthere are 2g no moving parts, thereby eliminating the possibility of theeconomizer getting out of adjustment or becoming otherwise impairedthrough Wear.

A further object is to provide an economizer for carburetors in whichthe amount of fuel passing through the fuel Venturi tube is renderedproportionate to the actual oper ating requirements of the engine upon\vhich the carburetor is used.

A further object is to provide an economizer for carburetors which isintended for permanent adjustment at the time the carburetor is built,but which may be re-adjusted as for adaptation of the carburetor to anengine of a different type from which the carburetor was initiallyintended by the substitution of parts of the economizer for similarparts differing only as to size. i

Another object is to provide in a carburetor of the fuel lift typeutilizing for its fuel nozzle ay suction multiplying Venturi tubethrough which primary air to the earburetor is admitted, means formaintaining relatively high depression in the induction passage at themouth of theiventuri.

A further object is to provide an economizer for carburetors which isextremely simplein construction and in which parts thereof afford aprotective housing for that' portion of the fuel Venturi tube subjectedto atmospheric pressure.

Other objects and advantages of my invention will appear more fully fromthe ,following description and from the accompanying drawing, in whichsimilar characters of reference indi-cate similar parts throughout theview. In the drawing: l

The figure is a sectional view of a carburetor embodying the economizer.

The carburetor illustrated herein is that type of carburetor which Ihave fully illustrated and explained in my co-pending application forpatent on vacuum feed carburetor, Serial No. 155,598, filed December 18,1926, and consists chieiiy in an induction chamber l and air inlet 2,and a delivery passage 3 having its mouth adapted for registration withthe intake manifold 4 of an internal combustion-engine. The chamber land the passage 3 constitute and shall hereinafter be referred to as theinduction passage of the carburetor. The carburetor furtherconsists of aspring pressed air valve 5 which opens to permit the passage of air fromthe air inlet 2 to the induction passage by engine suction, anda fuelchamber 6 which communicates by means of a passage 7 to the throat 8 ofa fuel delivery Venturi tube 9. The Venturi tube 9 is projected throughthe side walls of the induction chamber l and has its intake orifice 10subjected to atmospheric pressure.

As explained in the co-pending application referred to, the passage ofair through the Venturi tube 9 creates relatively high suction at thethroat 8 of the Venturi tubeand lfuel is drawn from the chamber 6 intothe moving air column in the -Venturi tube whereupon it is delivered inatomized state to the induction chamber 1.

I attain the highest degree of eiieiency in the operation. of theVenturi tube 9 by constructing the `secondary spring pressed air valve 5at its periphery in such a manner as to deflect air passing between thevalve and its seat 5a outwardly toward the walls 30 of ftheinductionvchamber 1 immediately above the valve and in disposing themouth `or delivery orifice 31 of the Venturi tube 9 immediately abovethe valve 65. For this purpose the valve 5 has the under surface of itsperipheral portion formed with a slight inclined surface 32 which liesnearly in a horizontal plane. The upper surface of the valve seat 5alies in a horizontal plane. Air passing through the valve is deiiectedfrom surface 32 toward the Walls 30 of the induction chamber andthereafter the separated air stream merges at a point slightly above theVenturi tube 9 where it -may pass through the delivery port 3 of thecarburetor. The region above the valve 5 is therefore maintained atslightly higher depression than is any other portion of the inductionchamber so that a relatively increased flow of primary air duced. Thisarrangement results in the highest possible efficiency in the suctionmultiplying property of the Venturi as the quantity of air passingthrough the tube in a given time determines the suction multiplyingcharacteristics of the tube.

A butterfly throttle valve 11 is disposed in the passage 3 for thepurpose ofcontrolling the passage of fuel from the induction passage tothe manifold 4.

The valve 11 is shown in full lines at idle position and at ll-A indotted lines at part throttle position. At ll-B in dotted lines thethrottle is represented at wide open position as when the automobile istraveling at its maximum speed or full load.

The economizer serves to limit the passage of air through the Venturitube 9 at such times as it is desirable to deliver a reduced supply offuel to the induction chamber for the purpose of economical operation.It consists in a cap 15 which entirely surrounds the exposed portions ofthe Venturi 'tube 9 includingthe intake orifice 10. A chamber 16 is thusformed which houses the intake end of the Venturi tube 9. The cap 15 issecured to the body of the carburetorby the provision of an externalthreaded portion 17.

The chamber 16 communicates by means of a passage 18 with an opening 19through the wall of the passage 3 at -a point slightly be- Vneath thethrottle 11 when the throttle is in idle position, as shown in fulllines in the figure. Means for limiting the amount of air which may passfrom the chamber 16 through the passage 18 and out through the opening19 by virtue of depression in the passage 3 conslss in a plug 20 havinga restricted bore 21 therethrough which is interposed between thepassage 18 and thefopening19 in the man# ner illustrated. This plug 20is removable and may be replaced with a similar plug having a larger orsmaller bore 21 so'as to adapt the economizer to various demandsdependent upon the type of engineV upon which the carburetor is used.

A plug 22, having a restricted bore 23, is projected through the outerwall of the cap 15 and secured thereto by external threads 24:

which engage with an internally threaded neck portion 25 formed in thecap and performs the function of limiting to a degree the amount of airwhich may pass from the atmosphere into the chamber 16.

The operation of my improved economizer for carburetors is entirelyautomatic. At idle position as when the throttle 11 assumes the positionshown in the full lines in the drawing, the depression in the inductionpassage at-the opening 19 and at the delivery end of the Venturi tube 9is the same and air is free to pass from the atmosphere through the bore23, the major portion ofl which passes through thevVenturi tube 9 tocreate a relatively high suction at the throat 8 of the Venturi tubewhich lifts fuel from the chamber ,6 through the passage 7 into the IVenturi tube for delivery into the induction chamber. A very smallamount ofair will pass up through the passage 18 from the chamber 16-andout of the opening 19 but not in sufhcient quantities to in any wayreduce the free passage of air through the Venturi tube 9.

At such times as the throttle valve 11 as' passage 18 and bore 21effects a reduction of the amount of air which is'available in thechamber 16 for passage through-'the Venturi tube 9. Inasmuch as thequantity of fuel delivered through the Venturi tube depends .upon thequantity of air which asses there.

through, the delivery of fuel at t is time will be less than would occurif air was not being exhausted from the chamber 16 to the enginemanifold in the manner described. This operation results in a highlyeconomical functioning of the carburetor.

When, however, the throttle 11 assumes the position shown in the dottedlines at ll-B as for full load or maximum speed, then it .becomesnecessary to have maximum delivery of fuel.A At this time the opening 19and the inner end of the Venturi tube 9 are subjected to the samedepression, which depression is substantially the same as that in theengine manifold 4. The result is that the Venturi tube 9 is free tooperate to maximum capacity for the delivery of fuel much the same as itdoes when the throttle 11 is in the position,v shown in full lines. n

I claim: I 1. An economizer for carburetors having an induction passageand a fuel delivery Venturi tube, one end of which extends into saidinduction passage and the other end of which extends exteriorly of thelarburetorand dependent in its operation upon pressure at theatmospheric end of said tube, comprising ineans, including an airpassage communi eating with said induction passage at one end and withthe atmospheric end of said Ven* turi tube, for reducing the pressure atthe atmospheric end of the Venturi tube whereby the amount of fueldelivered into the induction passage is reduced.

2. An economizer for carburetors having an induction passage, a throttlevalve in said passage and a fuel delivery Venturi tube, one end of whichextends into said induction passage and the other end of which extendsexteriorly of the carburetor, and dependent in its operation uponpressure 'at the atmospheric end of said tube, comprising means,including an air passage communicating with said induction passage atone end and with the atmospheric end of said Venturi tube for reducingthe pressure at the atmospheric end of the Venturi tube, whereby theamount of fuel delivered into the induction passage is reduced, saidmeans being dependent in its operation upon the relative/positions ofsaid throttle valve and that end of said passage communicating with theinduction passage.

An economizer for carburetors having an induction passage, a throttlevalve in said passage and a fuel delivery Venturi tube, one end of whichextends into said induction passage and the other end of Which extendsexteriorly of the carburetor, and dependent in its operation upon thepassage of air from theV atmosphere through the Venturi tube byatmospheric pressure, comprising a chamber surrounding the air inlet endof the Venturi tube, said chamber having an opening therethroughcommunicating with the atmosphere and a passage communicating at one endwith said chamber and at the other end With said induction passage at apoint adjacent to said throttle valve .whereby the amount of fueldelivered into the induction passage is dependent upon the relativeposition of the throttle valve and the adjacent orifice of saidlastnamed passage.

i. In combination, a carburetor hav'A a; an induction chamber, a fueldelivery nozze extending into the chamber dependent in its opeation uponthe passage of air at atmospheric pressure therethrough, and an airvalve forcontrolling the flow of air into the induction chamber, saidvalve being constructed so as to deiiect air entering the inductionchamber away from the center of the chamber. said nozzle having itsdelivery oriiice 'substantially at the center of the induc tion chamber.

5. In combination, a carburetor having an induction chamber, a fueldelivery nozzle dependent in its operation upon the passage of primaryair therethrough, and an air valve for controlling the admissionofsecondary air into the chamber at atmospheric pressure, said air valvebeing so constructed as to deiiect air outwardly and away from thatregion of the induction chamber immediately above the valve, said fuelnozzle having its delivery orifice above-the central portion of thevalve and in the area of relative depression caused by deiiectionof theair in the secondary air stream.

6. In combination, a carburetor having an induction chamber, a fuel feedVenturi tube extending into the induction chamber through which fuel isdelivered upon the passag-e of primary air through said venturi,asecondary air inlet for the induction cham ber, a valve for controllingthe admission of secondary air to the induction chamber, said air valvebeing so constructed as to create a region of relative depression in theinduction chamber imlnediately above its head, said fuel venturi havingit-s delivery orifice terminating at a point above the head of the valveWithin the region of relative depression,

7. In combination a carburetor having lan induction chamber, a fueldelivery nozzle eX- tending into the chamber dependent in its operationupon the passage of air therethrough, and an air valve for controllingthe ioW of air into the induction chamber, said lvalve being constructedso as to deiect air entering the induction chamber away from the centerofthe chamber and the delivery end of said fuel delivery nozzlepositioned in the diametrical center of the induction chamber andimmediately above said air valve.

In Witness whereof, I hereunto subscribe my name this 29th day of June,1922.

ROBERT F. BRACKE.

